单项选择题
A pumproom is suspected of accumulating gases after a ventilation machinery breakdown. Where should the combustible gas indicator case be placed when testing the pumproom atmosphere for combustible gases?（）.
A.In the lower level of the pumproom B.In the middle level of the pumproom C.In the upper level of the pumproom D.On the deck outside the pumproom
单项选择题 A partial deck in a hold is called a(n)（）.
单项选择题 A device used to tighten up remaining slack in wire rope when you are making up to a tow in inland waters is a（）.
单项选择题 A bridle for an ocean tow consists of（）.
